Excavators of the above type operate on the "back hoe" principle and it is usual for the same machine to both rip and shovel earth in scoop or hole making operations. Usually separate implements may be attached to the dipper arm of the machine to independently effect the different operations. Recently however it has been successfully proposed that the ripper be maintained operatively positioned on the machine and used to support a detachable scoop when the latter is required to be used. The detachable mounting of the scoop on the ripper while being an appreciable improvement on the interchangeable implement arrangement nevertheless requires a second workman to assist in the mounting or release of the scoop and also skill is required to locate the ripper and scooper in the proper relationship to enable mounting of the scoop to be effected.